Yang Guang, Hou Xiaoyue, Lu Jing, Wang Minbo, Wang Yuhan, Huang Yichen, Liu Qitong, Liu Shu, Fang Yaowei
Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222000, China; College of food science and engineering, Jiangsu Ocean University, Lianyungang 222005, China.
College of food science and engineering, Jiangsu Ocean University, Lianyungang 222005, China.
Int J Biol Macromol. 2022 Apr 1;203:671-678. doi: 10.1016/j.ijbiomac.2022.01.167. Epub 2022 Feb 2.
In this study, chitin deacetylase from Microbacterium esteraromaticum MCDA02 (MeCDA) was purified by ammonium sulfate precipitation, anion exchange chromatography, and superdex column chromatography. The molecular weight of purified MeCDA was approximately 26 kDa. The optimum pH and temperature of purified MeCDA were 8.0 and 30 °C, respectively. The enzyme activity is enhanced by metal ions K and Sr and inhibited by Co, Cd, and EDTA. The degree of deacetylation through enzymatic modification of MeCDA was removed an average of 32.75% of the acetyl groups for ɑ-chitin by acid-base titration. Meanwhile, MeCDA can catalyze the hydrolytic cleavage of the acetamido bond in GlcNAc units within chitin oligomers and polymers. Hence, the MeCDA is a potent chitin decomposer to catalyze chitin and chitin oligosaccharides deacetylation to prepare chitosan and chitosan oligosaccharide. This is a value-added utilization of chitin based biological resources.
在本研究中，通过硫酸铵沉淀、阴离子交换色谱和Superdex柱色谱法对来自芳香酯微杆菌MCDA02（MeCDA）的几丁质脱乙酰酶进行了纯化。纯化后的MeCDA分子量约为26 kDa。纯化后的MeCDA的最适pH和温度分别为8.0和30℃。金属离子K和Sr可增强该酶的活性，而Co、Cd和EDTA则对其有抑制作用。通过酸碱滴定法测定，经MeCDA酶促修饰的脱乙酰度平均可去除α-几丁质中32.75%的乙酰基。同时，MeCDA可催化几丁质寡聚物和聚合物中GlcNAc单元内酰胺键的水解断裂。因此，MeCDA是一种高效的几丁质分解酶，可催化几丁质和几丁质寡糖的脱乙酰作用，以制备壳聚糖和壳聚糖寡糖。这是对几丁质基生物资源的增值利用。
